A Fine Line

Frequently humorous and always engaging, this suspense novel takes off at an airport, where Jack Mann finds the barrel of a gun in his ear. After he manages to kill his assailant, Mann, a retired cop, drives off wondering what to do with the contents of the dead man's gym bagmillions in cash. What Mann gradually figures out is that the money belongs to the Mafia, and was stolen by the IRA. In New York on a terrorist mission, the young leader of the Irish plot is pursued by police and thugs. But so is Jack, who is eventually suspected of having the money. Through a pleasant romance with an Irish barmaid in Queens, Jack is drawn inexorably into the center of the action, and he, too, ends up chasing the terrorist. Excellent pacing adds to a slam-bang ending, and all the characters are credible and interesting. (Mar.)